Ronald Guinto, 32, was arrested at his current workplace, Mira Vista Elementary School in El Cerrito, on Wednesday morning on suspicion of 11 counts of lewd acts upon a child under 14 years old, two counts of forced oral copulation and one count of assault with intent to commit sodomy, according to police.

Richmond police Lt. Andre Hill said Thursday that the Contra Costa County District Attorney’s Office is still reviewing the case but has confirmed it plans to file multiple felony charges against Guinto.

The teacher’s arrest stems from a police investigation launched in November after several students at Making Waves Academy in Richmond, where Guinto previously worked, reported that he had sexually abused them.

Investigators believe the alleged abuse occurred during camping trips and “various excursions where he was the lead person in charge,” Hill said.

Making Waves reported the allegations to police, conducted its own investigation and fired Guinto, he said.

“Our first priority is the safety and well-being of our students. To our knowledge the alleged misconduct took place outside of Making Waves Academy,” Making Waves Academy CEO Alton Nelson said in a statement.

“The charges brought are obviously very serious. We are helping the authorities and, as always, providing support to our community,” he said.

About two months after police began their investigation, Guinto was hired full-time as a teacher at Mira Vista Elementary, where he was arrested after arriving at work around 7:45 a.m. Wednesday.

The arrest and the allegations came as a shock to administrators at the school and the West Contra Costa Unified School District, school board president Charles Ramsey said.

Ramsey described Guinto as a “popular, well-liked” seventh-grade English and science teacher who was hired in part because of his perceived ability to work with academically struggling students.

The district has not received any reports of alleged sexual misconduct at Mira Vista, he said.

Ramsey said Guinto cleared a fingerprint background check in December and had no criminal history. He is not listed in the California Megan’s Law database of sex offenders.

Administrators never did a reference check on him because he had already worked at many of the district’s schools as a frequent substitute teacher between 2008 and 2011, so was considered a re-hire, the school board president said. The school district is not required to check references for re-hired staff.

“There was no sense that as a re-hire, we needed to do a reference check,” he said.

Ramsey added that Guinto’s “performance had been so stellar” that he was offered a full-time teaching contract two weeks ago.

The teacher was also set to take groups of students on an overnight trip to Yosemite next month, he said.

The school board president said he plans to propose an update to the district’s policy to make employer reference checks mandatory, and said this case has been “a valuable lesson learned that no matter what the circumstances, we also need to do a reference check.”

Hill said police quickly obtained a warrant for Guinto’s arrest after learning only on Tuesday that Guinto was currently working as an elementary school teacher.

“We would expect any employer to screen any potential applicant that’s working around kids, whether they’ve worked there before or not, to call the last place they worked…to make sure they were in good standing,” he said.

Guinto remains in custody in county jail in Martinez in lieu of $1.4 million bail.